Apparatus and method for the hot filling of beverages

ABSTRACT

The invention relates to a method of producing beverage containers ( 10 ) with the steps:
         producing a plastics material container ( 10 ), wherein the plastics material container ( 10 ) is produced from a plastics material pre-form by means of a shaping device ( 2 );   conveying the container ( 10 ) to a filling device ( 4 )   filling the container ( 10 ) with a liquid and, in particular with a beverage, wherein the liquid is filled into the container ( 10 ) at a temperature which is above 50° C.,
 
wherein
 
the container ( 10 ) is sterilized between a separating device arranged upstream of a pre-form inlet of the shaping device ( 2 ) and the filling device ( 4 ).

The present invention relates to a method and an apparatus for producing filled beverage containers and, in particular to a method and an apparatus in which beverages are filled hot. It is known from the prior art that various beverages such as for example iced tea are filled hot. This hot filling poses problems, in particular in the case of plastics material containers or PET containers. In the hot filling of PET containers in fact the thermal stability of the material and the vacuum stability of the container represent a major challenge. The material of PET has a relatively low glass transition temperature of approximately 75° C. This is not sufficient for the filling temperature of sensitive products which as a rule is between 85° C. and 92° C. For this reason the material is thermally crystallized during the treatment in the stretching blow moulding machine. This is carried out by way of a high pre-form temperature and by way of heated blow moulds (temperatures of between 120° C. and 160° C.). On the other hand, however, this leads to a significantly higher energy consumption since cooling of the container is additionally required by way of compressed air before deformation occurs. A further drawback is the limited output performance on account of the necessary crystallization period in the blow mould.

The higher the filling temperature, the more problematic the thermal stability becomes, and the output performance has to be drastically reduced in part. In addition, this procedure results in a relatively high weight of the containers.

DE 36 50 667 T2 describes a method of producing a deformation-resistant polyester container which is capable of being hot filled. In this case a plastics material pre-form is produced, and it is heated and placed in a blow mould cavity. Furthermore, it is necessary to observe specific drawing ratios of the wall of the pre-form which are between 8:1 and 12:1. In addition, the temperature of the re-heated pre-form is maintained between 82° C. and 121° C.

DE 698 02 357 T2 describes an apparatus for the sterile filling and packing of foods. This apparatus has a sterilization portion for sterilizing packing containers filled with solid or liquid foods as well as a packing portion for hermetically sealing the packing containers.

A filling machine with liquid circulation is known from EP 1 559 674 B1. In this case a charge is also filled hot into bottles and, in order to prevent the charge from cooling in the filling elements, the charge is conveyed in the hot state in at least one flow path including the filling elements whilst interrupting the filling process.

A further method of hot filling beverages is known from U.S. Pat. No. 5,251,424. In this case too a plastics material container is made available and after that the hot beverage is filled into it. After that the container is closed and the contents of the container are held under pressure

A method of low-germ filling of plastics bottles is known from DE 195 20 925 A1. In this case after the filling and closure each container is subjected to a thermal after-treatment in which the charge is held in the interior of the respective container at a temperature of at least 60° C.

The object of the present invention is to treat the respective plastics material containers as gently as possible even in the case of beverages which are to be filled hot. This is attained according to the invention by a method and an apparatus in accordance with the independent claims. Advantageous embodiments and further developments form the subject matter of the sub-claims.

In the case of a method according to the invention for producing filled beverage containers a plastics material container is first produced, the plastics material container being produced from a plastics material pre-form by means of a shaping device. After that, the container is conveyed to a filling device and is filled with a liquid and, in particular with a beverage, in which case the liquid is filled into the container at a temperature which is above 50° C.

According to the invention the container is sterilized at least in part between the shaping device and the filling device, or expressed in more precise terms, between a separating device for separating the plastics material pre-forms arranged upstream of a pre-form inlet of the blow moulding machine and the filling device. It is preferable for an inner wall of the container to be sterilized at least in part and is preferably sterilized completely. In addition, however, it is also possible for sterilization of an outer surface of the container to be carried out at least in part. In this way, it is preferable for this separating device for separating the plastics material pre-forms also to be regarded as being a component part of the shaping device within the context of this description. It is preferable for the separating device to be arranged between the inlet of the shaping device and the filling device.

The term “blow moulding machine” refers in the following not only to the actual blow moulding module which shapes the plastics material pre-forms into plastics material containers, but also to apparatus arranged upstream of this blow moulding module, such as in particular but not exclusively a heating device or a furnace, which heats the plastics material pre-forms. In this case the pre-form inlet can be in particular that area at which the pre-forms arrive in the aforesaid heating device. In particular, sterilization in an area of the heating device would thus also be possible. It would also be possible, however, for the pre-forms heated in the heating device to be sterilized before, during or after their entry into the blow moulding module.

The shaping device is in particular a blow moulding machine and, in a particularly preferred manner, a stretching blow moulding machine. The high filling temperature is necessary in particular on microbiological grounds. In this case the charge has to be heated to a temperature dependent upon the product in order to achieve an adequate sterilization effect against the germ spores etc. which exist. As a result of this destruction of pathogens a longer storage life of the charge is achieved. It is preferable for the charge to be filled at a temperature which is above 60° C., preferably above 70° C. and in a particularly preferred manner above 75° C. In order to ensure that all pathogens are destroyed even on the path of the product into the container and in the container, the product has to be filled hot and not only sterilized in the course of a heating of short duration. In this case the prior art provides for a certain standing time of the hot liquid in the bottle, which as a rule lasts between one and five minutes for this microbiological safeguard. On the other hand, this very standing time has the effect that the PET container is difficult to keep dimensionally stable since the strength of the material is sharply reduced.

With the method proposed according to the invention it is therefore made possible for a product to be filled in a microbiologically safe manner without the complication of an aseptic procedure being required. On account of the heavy weight of the bottles, the hot filling already described in the prior art is economic to only a limited degree and is improved by way of the present invention in such a way as to result in an economic filling method. It is advantageous for the sterilization of the container to be carried out by acting upon it with a sterilizing agent and, in particular, with hydrogen peroxide gas.

It is advantageous for the container to be sterilized in the shaping device. In this case it is possible for the containers to be sterilized in the shaping device for example of the blow moulding machine. This sterilization of the container produced is now combined with the hot filling in order to avoid in this way the necessary standing time of the container at a hot temperature.

In the case of a further advantageous method the container is cooled after the filling (in particular immediately afterwards). In this way an additional protection of the containers is possible. It is thus possible for the containers to be conveyed directly into a heat exchanger downstream of the filling device. In this case, as compared with the prior art, the conveying path is dispensed with which is otherwise present between the filling device and this heat exchanger.

In the case of a further advantageous method the cooling of the filled containers is carried out without further head space sterilization of the filled containers. It is preferable for the cooling to be carried out at a temperature of below 50° C. If products, the temperature of which is above 85° C., are filled, sterilization of the filling device itself is also effected by the product.

In addition, it is possible to dispense with neck sterilizers. In this way, the container is cooled down from the critical temperature range of over 80° C., in particular after the filling, so that the PET does not pass into a weakened state in which it could become dimensionally unstable. It is preferable for the shaping unit and the filling device to be operated in a block arrangement or in synchronism, and it is particularly preferred for these blocks to be complemented by a heat exchanger.

It is advantageous for the container to be cooled by being acted upon with a flowable medium. It thus can be sprayed with water for example in order to be cooled in this way. Cooling with air, however, would also be possible.

In the case of a further advantageous method the container is closed immediately after the filling. It is advantageous for the disinfection or the sterilization of the individual closures to be carried out during this. In this case too this sterilization can be carried out with a gaseous medium, such as in particular but not exclusively hydrogen peroxide (H₂O₂).

In the case of a further advantageous method the closure of the container is likewise sterilized. It is advantageous for the closure to be sterilized before the closing procedure. In this case, in particular, sterilization of the interior of the closure takes place, i.e. of that region which bounds the interior of the closed container.

It is advantageous for the container to be conveyed through a sterile environment between the shaping device and the filling device. In this way it is possible for the container no longer to be contaminated after the shaping procedure. This can be for example a sterile room which extends from the shaping device to the filling device. It is thus advantageous for the filling device also to adjoin the shaping device at a relatively short distance and, in a particularly preferred manner, directly.

It is advantageous for the container to be acted upon with a gaseous medium after being filled. Expressed in more precise terms, a gaseous medium, and in particular nitrogen, is introduced into the container after the filling procedure. In this way it is possible for air to be forced out of the head space of the containers in order to prevent contamination in the head space of the containers as well in this way.

In addition, the present invention relates to an apparatus for producing filled containers, this apparatus having a shaping device which shapes plastics material pre-forms to form plastics material containers. In addition, a conveying device is also provided which conveys the plastics material containers away from the shaping device and, in addition, a filling device is also provided which is arranged downstream with respect to the shaping device along a conveying path of the plastics material containers and which fills the containers with a liquid. In this case the filling device is designed in such a way that it fills the liquid at a temperature of more than 50° C. into the containers.

It is advantageous for the apparatus to have a sterilization device which is arranged between a separating device (for separating the plastics material pre-forms) arranged upstream of a pre-form inlet of the shaping device and the filling device and which sterilizes the containers (10).

An arrangement between the shaping device and the filling device is to be understood as being that in this case the sterilization device can also be arranged in a region of the shaping device (or in the region of a separating device for separating the plastics material pre-forms which is optionally arranged upstream of this shaping device), and for example the plastics material pre-forms are also sterilized shortly before or even during the shaping procedure. It is advantageous, however, for the sterilization device to be arranged downstream of the shaping device and thus to sterilize the containers already produced.

In the case of an advantageous embodiment the apparatus has a application device which is arranged downstream of the filling device along the conveying path of the plastics material containers and which acts upon the filled containers with a flowable and preferably gaseous medium. Expressed in more precise terms, the liquid present in the containers is acted upon with the gaseous medium. It is advantageous for the gaseous medium to be nitrogen. In this case it is possible for this nitrogen also be introduced in a liquid form.

As a result of the introduction of this medium, in particular in a gaseous form, a displacement of the oxygen present in the filled container or a minimization of the oxygen is made possible. If the oxygen is introduced in a liquid form, a build-up of pressure can additionally be achieved in the container, which build-up of pressure for example counteracts the effect of the contraction of the liquid present in the container.

In the case of a further advantageous embodiment the apparatus has a cooling device arranged downstream of the filling device for cooling the filled containers. It is preferable for the cooling device to cool the containers to a temperature which is between 50° C. and 75° C., preferably between 60° C. and 75° C. and in a particularly preferred manner between 65° C. and 75° C.

In this way, the container is no longer so highly stressed thermally as in the prior art. It is thus also possible for the container to be produced in a more inexpensive manner, in which case for example use is made not of a heat setting method but only of a hot relaxation method. In addition, the weight of the containers can be significantly reduced. A weight of the containers as used in aseptic applications has been found to be particularly suitable, without, on the other hand, the high costs of the operating expenses of aseptic plants having to be applied.

An application of the invention is possible both for a conventional hot filling and for a hot filling with subsequent stressing with gas (also referred to as NitroHotFill by the Applicants). In particular, a high degree of efficiency can be assumed for the last-named method.

It is advantageous for a closing device for closing the containers to be arranged upstream of the cooling device. This means that it is preferable for the containers first to be filled, then to be closed and finally to be cooled. It is advantageous for the closing means to be provided substantially immediately downstream of the application device, which acts upon the liquid with the gaseous medium.

In the case of a further advantageous embodiment a sterile room, through which the container is conveyed, is arranged between the shaping device and the filling device. The provision of this sterile room ensures that contamination of the container after the production thereof can no longer occur. It is advantageous for the shaping device to be followed substantially directly by the filling device. It can thus be provided that only one transfer star wheel is provided as a conveying device between the shaping device and the filling device. In addition, it would be possible for the shaping device and the filling device to be arranged in the same housing. In the case of a further advantageous embodiment the apparatus has a labelling device which applies a label to the container. In this case this labelling device is advantageously arranged downstream of the closing device, which closes the containers already filled. It is advantageous for the labelling device also to be provided downstream of the above-mentioned cooling device for cooling the filled containers.

A drying device, which dries an outer wall of the containers, for example by acting upon it with an air flow, can also be provided between the filling device and the labelling device. The labelling device can be a labelling device which applies self-adhesive labels to the containers. Labelling devices would also be possible however, which apply the labels to the containers by means of an adhesive, or even those labelling devices which apply shrink-on labels to the containers.

Further advantages and embodiments are evident from the accompanying drawings. In the drawings

FIG. 1 shows a plant for handling containers from the prior art, and

FIG. 2 is a diagrammatic illustration of a plant according to the invention.

FIG. 1 is a diagrammatic block diagram of a plant 100 according to the prior art. In this case a shaping device 2, such as in particular a stretching blow moulding machine, is provided, which shapes the plastics material pre-forms to form plastics material containers. For this purpose the plastics material pre-forms are first conveyed through a heating device 48 such as a furnace and are then supplied in a heated state to the shaping device 2. This shaping device 2 is followed by a filling device 4 in which the containers are filled with a beverage. Following this filling the filled containers are conveyed to a heat exchanger 6 by way of a conveying path 52, 54 and 56. In this case the reference number 56 relates to a sterilization unit for a head space of the containers.

The heat exchanger 6 is followed in turn by a conveying path 58 for the filled and also closed containers as well as a labelling device 12 which provides the containers with labels. The reference number 14 relates to packing devices which for example form groups from a plurality of containers. Finally, the reference number 16 designates a palletizing means.

It is clearly evident that the containers filled with the hot beverage are conveyed away over a relatively long conveying path (52, 54, 56). In the prior art the hot beverage can act upon the walls of the containers during this time and these walls can become unstable as a result

FIG. 2 is an illustration in the manner of a block diagram of an apparatus 1 according to the invention. In this case too a shaping device 2 and a filling device 4 are again provided. The reference number 5 relates to a conveying device which conveys the containers from the shaping device [into] the filling device. This conveying device can be for example a conveyor belt or a circulating conveyor chain.

In addition, however, a sterilization device 8, which sterilizes the shaped containers, is provided additionally between the shaping device 2 and the filling device 4. As mentioned above, this can be a sterilization device which acts upon the containers with gas, for example H₂O₂. It would also be possible, however, for radiation devices to be used which irradiate the containers with radiation such as in particular UV radiation, X-rays or electrons.

In particular, in this case the inner wall of the containers is sterilized, but sterilization of the outer wall would also be additionally possible. The reference number 20 relates to a clean room which is arranged in the region between the shaping device 2 and the filling device 4. This ensures that the shaped containers leave this sterile room 20 again in particular only in a closed state in which contamination is eliminated. The reference number 22 accordingly designates a closing means which closes the filled containers.

In this way it would also be possible for the pre-forms to be already sterilized after entering the furnace in which they are heated for the blow moulding procedure, or even during the passage through this furnace. In this way nozzles which act upon the pre-forms with a sterilizing agent could be arranged for example above a conveying device for the pre-forms. In addition, the sterilization devices could also be arranged downstream of the furnace or between the furnace and the actual blow moulding stations. It is also possible for the temperature at which the action of the sterilizing agent is to take place to be indirectly determined by the arrangement of the sterilization device. In addition, it would also be possible for a plurality of sterilization devices to be provided which are arranged for example at different locations along the conveying path of the containers. In this case these different sterilization devices could also apply different methods, for example sterilization by means of UV or electron radiation and a further sterilization by means of H₂O₂. In addition, it would also be possible for the pre-forms to be immersed in a bath with sterilizing agent so that in this way sterilization of both the inner wall and the outer wall of the pre-forms is carried out.

In this way, it is possible for both sterilization of the pre-forms and sterilization of the plastics material containers just produced to be carried out. In addition, it is also possible for the containers to be rinsed with warm water in the course of a sterilization process. It would also be possible for the outer areas of the containers to be rinsed by a sterilizing agent being directed onto an opening of the containers. The interior of the containers can also be rinsed with (sterile) air after being acted upon with the sterilizing agent.

For the purpose of sterilization it is also possible for a plurality of spray nozzles to be provided which direct the sterilizing agent onto the surface of the containers. In this case the jet of the sterilizing medium can be directed for example onto the lateral faces or the base surface of the containers. It is also possible for movable spray nozzles to be used. Saturated steam can also be used for the sterilization. In addition, it is also possible for sterilization of the surface of the containers to be achieved by continuously acting upon the latter. The sterilizing agent can also be heated before the containers are acted upon by it.

The filling device is immediately followed in this case by the cooling device 6 which cools the filled and closed containers. In this way, the conveying path 52, 54 and 56 illustrated in FIG. 1 is dispensed with. In this case the containers can be conveyed for example on a belt and preferably arranged adjacent to one another through this cooling device. In this cooling device the containers can then be acted upon from the outside with a flowable cooling agent such as for example water, but optionally also with air. In addition, a drying device can be further provided which dries the outer wall of the containers for the purpose of labelling for example.

At the same time a stressing device 24, which acts upon the filled containers with nitrogen for example, can also be provided in this region.

The devices downstream of the cooling device 6 once again correspond essentially to the arrangement shown in FIG. 1. In this case the reference number 46 relates to a CIP unit for cleaning the filling device. The reference number 42 designates a pasteurization unit for pasteurizing the liquid. The reference number 44 designates a mixer which can likewise be used with a multiplicity of beverages. As a result of the procedure according to the invention a sterile container arrives in the filling device. On the conveying path between the shaping device 2 and the filling device 4 it is preferable to ensure that no new contamination enters the container.

To this end it is possible for the interior of the container to be rinsed (in particular with nitrogen). After that, the container is hot filled at the appropriate filling temperature, this high filling temperature being necessary—as mentioned above—in order to keep the filling device sterile. The container itself is ideally not contaminated itself. The closing device 22 is preferably provided with a closure disinfection means. In addition, the container is transferred—as mentioned above—on the shortest path, in particular by way of a conveyor belt, directly into the cooling device 6 and it is cooled to a lower temperature there. It is preferable for the containers to be guided individually upstream of the heat exchanger in the heat exchanger and in a stream of containers.

The Applicants retain the right to claim all the features disclosed in the application documents as being essential to the invention, insofar as they are novel either individually or in combination as compared with the prior art

LIST OF REFERENCES

-   1 apparatus -   2 shaping device -   4 filling device -   6 heat exchanger -   8 sterilization device -   12 labelling device -   14 packing devices -   16 palletizing means -   20 clean room -   22 closing means -   24 application device -   42 pasteurization unit -   44 mixer -   46 CIP unit -   48 heating device -   52, 54, 56 conveying path -   100 apparatus, prior art 

1. A method of producing beverage containers with the steps: producing a plastics material container, wherein the plastics material container is produced from a plastics material pre-form using a shaping device; conveying the container to a filling device; filling the container with a liquid and, in particular with a beverage, wherein the liquid is filled into the container at a temperature which is above 50° C., wherein the container is sterilized between a separating device for the plastics material pre-forms arranged upstream of a pre-form inlet of the shaping device and the filling device.
 2. A method according to claim 1, wherein the container is sterilized in the shaping device.
 3. A method according to claim 1, wherein the container is cooled after the filling.
 4. A method according to claim 3, wherein the container is cooled by being acted upon with a flowable medium.
 5. A method according to claim 1, wherein the container is closed immediately after the filling.
 6. A method according to claim 1, wherein a closure of the container is likewise sterilized.
 7. A method according to claim 1, wherein the container is conveyed through a sterile environment between the shaping device and the filling device.
 8. An apparatus for producing filled containers, with a shaping device which shapes plastics material pre-forms to form plastics material containers, with a conveying device which conveys the plastics material containers away from the shaping device, and with a filling device which is arranged downstream with respect to the shaping device along a conveying path of the plastics material containers and which fills the containers with a liquid, wherein the filling device is designed in such a way that it fills the liquid at a temperature of more than 50° C. into the containers, wherein the apparatus has a sterilization device which is arranged between a separating device arranged upstream of a pre-form inlet of the shaping device and the filling device and which sterilizes the containers.
 9. An apparatus according to claim 8, wherein the apparatus has a application device which is arranged downstream of the filling device along the conveying path of the containers and which acts upon the filled containers with a flowable medium.
 10. An apparatus according to claim 8, wherein the apparatus has a cooling device arranged downstream of the filling device for cooling the filled containers.
 11. An apparatus according to claim 8, wherein a sterile room, through which the container is conveyed, is arranged between the shaping device and the filling device. 